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Earliest known animal tracks discovered?

Another video from the USA which is no longer on the Internet, used to say about itself:

Rocks of the Proterozoic and Archean eras (The Precambrian) make up the inner gorge of the Grand Canyon on the Colorado Plateau. Proterozoic strata contains stromatolites, Chauria (small cap-like fossils) and Brooksella canyonensis, a fossil considered by some to be a fossil jellyfish and by others as a vendozoan (a group of puzzling late Precambrian firm impressions of what may be an extinct major category of life). The very hard rocks of the inner gorge belong to the Archean Era which in Arizona, may be younger in geologic time than nearer the continental nucleus where Archean rocks can be over three billion years old.

Faint, fossilized tracks of an ancient aquat­ic crea­ture sug­gests an­i­mals walked us­ing legs at least 30 mil­lion years ear­li­er than had been thought, some sci­en­tists say. But they ad­mit the lack of a fos­sil of the crea­ture it­self will probably fos­ter a healthy skep­ti­cism, and that re­search­ers will need to look for ad­di­tion­al ev­i­dence.

The track­s—two par­al­lel rows of small dots, each about two mil­lime­ters wide—are dat­ed to some 570 mil­lion years ago, to a per­i­od called the Edi­a­ca­ran. That pre­ced­ed the Cam­bri­an per­i­od, when most ma­jor groups of an­i­mals evolved.

Sci­en­tists once thought that mainly mi­crobes and sim­ple mul­ti­cel­lu­lar an­i­mals ex­isted be­fore the Cam­bri­an, but that idea is chang­ing, said Lor­en Bab­cock, pro­fes­sor of earth sci­ences at Ohio State Uni­ver­s­ity.

He pro­nounced him­self “rea­sonably cer­tain” a centipede-like ar­thro­pod or a leg­ged worm made the tracks. An ar­thro­pod is an in­ver­te­brate hav­ing joint­ed limbs and a seg­mented bod­y—a group that in­cludes in­sects.

Soo-Yeun Ahn, a doc­tor­al stu­dent at Ohio State and a co-author of the re­search, pre­sented the find­ings at the Ge­o­log­i­cal So­ci­e­ty of Amer­i­ca meet­ing Sun­day in Hous­ton.

Bab­cock said he found the tracks while sur­vey­ing rocks in the moun­tains near Gold­field, Ne­vada in 2000. “We came on an out­crop that looked like it crossed the Pre­cam­brian-Cam­bri­an bound­ary…. We just sat down and started flip­ping rocks over. We were there less than an hour when I saw it.”

The crea­ture must have stepped lightly on­to the soft seabed, be­cause its legs pressed only shal­low pin­points in it, Bab­cock said. But when he flipped over the rock bear­ing the lit­tle pits, the low-angle sun­light cast them in crisp shad­ow, he re­called. He could­n’t be sure of the crea­ture’s length or num­ber of legs, but he guessed it car­ried a centimeter-wide body on many spindly legs.

In 2002, oth­er re­search­ers re­ported a si­m­i­lar fos­sil trail from Can­a­da that dat­ed back to the mid­dle of the Cam­bri­an per­i­od, about 520 mil­lion years ago. Anoth­er set of tracks found in South Chi­na date back to 540 mil­lion years ago.

ScienceDaily (Feb. 3, 2010) — Trails found in rocks dating back 565 million years are thought to be the earliest evidence of animal locomotion ever found: here.

Canwest News Service – It’s a natural phenomenon that culminates in our time on Earth with the cheetah’s unbeatable sprint, the gazelle’s lightning retreat and — in human terms — Usain Bolt’s record-smashing 100-metre dash.

But scientists from Canada and Britain studying 565-million-year-old rocks in Newfoundland have discovered what they believe to be the earliest evidence of animal locomotion — a fossilized track left by an unknown creature that was, quite literally, life’s first trailblazer.

Its movement across the ancient sea floor — at a pace that was probably so slow as to be imperceptible — was made by a single, muscular “foot,” say the researchers, who compare the transport system of the unidentified species to the way today’s sea anemone slides toward food or away from harm.

The landmark find, detailed in the latest edition of the scholarly journal Geology, marks yet another major paleontological first for the Avalon Peninsula’s Mistaken Point, a top Canadian candidate to become a UNESCO World Heritage Site in recognition of its rich fossil record from the Ediacaran period of Earth history more than a half-billion years ago.

The newly discovered fossil trackways were made by the mysterious organism before the “Cambrian explosion” of animal life about 500 million years ago, best known from the world-renowned Burgess Shale fossil deposit in British Columbia.

In recent years, Canadian-led discoveries at Mistaken Point and other sites in Newfoundland have shed light on the Ediacaran’s era’s “pre-Cambrian” phase of evolution, a little-understood but crucial episode in the development of animal life that baffled even Charles Darwin.

The world’s first Ediacaran fossil was identified at a Newfoundland site in the 1870s by pioneering Canadian paleontologist Elkanah Billings. But it wasn’t until this decade that contemporary Canadian scientists, led by Queen’s University paleontologist Guy Narbonne, vindicated Billings’ theory that a form of animal life existed and can be found in fossils older than the Cambrian age.

“The markings we’ve found clearly indicate that these organisms could exert some sort of muscular control during locomotion,” Oxford University scientist Alex Liu, lead author of the new study, stated in a summary of the team’s discovery.

“This is exciting because it is the first evidence that creatures from this early period of Earth’s history had muscles to allow them to move around — enabling them to hunt for food or escape adverse local conditions.”

Liu’s Oxford colleague, Martin Brasier, and Memorial University of Newfoundland paleontologist Duncan McIlroy are co-authors of the Geology paper.

Liu acknowledged that “we aren’t able to say which Ediacaran organism created these trails,” but said the preserved track “is evidence that these creatures had muscles as well as the stiff tissues, such as collagen, that gave their soft bodies some rigidity” against the ocean’s ebb and flow.

“It is also evidence that the ecology of this ancient marine environment was quite complex, perhaps approaching the complexity of later epochs,” Liu also stated in the summary, adding that the trackway was found at a well-known locale at the Mistaken Point site “which has been traversed by countless researchers over the years. It just goes to show that these old rocks still have many new things to tell us.”

Narbonne generated global headlines in 2002 after discovering fossils in Newfoundland that were described as the oldest known traces of complex life on Earth.

In 2007, a British scientist working in New Brunswick discovered a 315-million-year-old fossilized trackway that it touted as the world’s oldest evidence of reptiles.

And last year, Canwest News Service revealed how a Canadian paleontologist had rediscovered a preserved copy of a famous and long-lost, 500-million-year-old fossil trackway made by the first animal known to have walked on land.

The landmark fossil from a site near Montreal had been preserved by legendary Canadian geologist William Logan in 1851, but the only surviving cast of the creature’s trail was lost for more than a century until it turned up recently in the storage area of a Massachusetts geological museum.